Computerized map programs allow a user to view a great deal of data. Some applications allow a client device to download map data that encompasses any location in the world at a detailed level. Such applications entail enormous quantities of data to include all the roads, shorelines, parks, etc. in the world. This data is too voluminous to be displayed or downloaded all at once. Accordingly, many applications provide map tiles with data at appropriate scales. Before delivering these tiles, the tiles must be generated and optimized for downloading to a client device.
Generating the tiles requires processing an enormous amount of computerized data about geographical features of the regions, which the computed tiles will represent. For individual tiles at a given zoom level, there may be far more data than can be displayed given the scale of the tile and the resolution of the map. For example, there may be many road segments known in the data that occupy an area represented by a single pixel of the map of which the tile is a part. Similarly, there may be multiple roads running parallel with each other within a line a single pixel wide on the map. Sending data representing each of these road segments would be a waste of bandwidth as the roads could not be displayed individually.